Harry d



(No Model.)

v H. D. BLUMENFELD.

GRINDING STONE.

No. 557,301. Patented Mar. 31.. 1896;

- I. INVENTOR dj'liiig w @zw Y v ATTUBNEK UNITED STATES PATENT OFFICE.

HARRY D. BLUMENFELD, on NEW YORK, N. Y.

GRINDING-STONE.

SPECIFICATION forming part of Letters Patent No. 557,301, dated March31, 1896. H

Application filed June 12, 1895. Serial No. 552,530. (No model.)

To all whom it may concern:

Beit known that I, HARRYD. BLUMENFELD, a citizen of the United States,and a resident of New York, county of New York, and State of New York,have invented certain new and useful Improvements in Grinding-Stones, ofwhich the following is a specification, reference being had to theaccompanying drawings, forming a part thereof, in which similar lettersof reference indicate corresponding parts.

This invention relates to grindstones and means for operating the same,and the object thereof is to provide an improved apparatus for operatinga grindstone and for supporting and automatically operatinga holder fora blade, bit, or other cutting device while the same is being ground.

The invention is fully disclosed in the following specification, ofwhich the accompanying drawings form a part, and in which Figure 1 is aside elevation of a grindstone and its supporting-frame provided with myimprovement; Fig. 2, a plan view thereof, and Fig. 3 an end view.

In the practice of my invention I employ a frame substantially of theusual construction, consisting of the sides A, the end pieces B,

V and the legs 0, on which is mounted the grindstone D, which isprovided with the usual shaft E and a crank F on one side of the frameand a power-wheel or pulley G on the other. Mounted at one end of theframe which supports the grindstone is my improved holder for the blade,bit, or other device to be ground, consisting of a base-plate H,supported at each end by two lugs or bars h, the lower ends of which areprovided with vertical slots h, through which pass set-screws 7L2, bymeans of which the base-plate of the holder is connected with thesidebars A of the main frame, and by means of which the holder isvertically adjustable on said main frame, as will be readily understood.

Mounted on the base-plate II of the holder is a sliding plate K, theunder side of which is provided with downwardly-extending longitudinalprojections 70, adapted to fit and slide within correspondinglongitudinal grooves or recesses in the upper side of the base-plate,and the sliding plate K has mounted thereon or formed integrallytherewith a longitudinal bar or plate L, the under central portion ofwhich is cut away, forming an opening I, and passing through the middleportion of the bar or plate L is a set-screw Z, all of which isclearly-shown in the drawings.

Connected with or formed on the base-plate H of the holder, at one endthereof, is a bar or extension M, in which is mounted, longitudinalthereof and in line with each other, two pulleys 'm and m, and thatportion of the extension or bar M between said pulleys may be entirelycut away, or partially so,as desired, and secured to the end of thesliding plate K of the holder at N is a cord n, which is passed aroundthe pulley m, back and around to the pulley m, and thence to the crankF, to which it is secured.

Secured to the side of the main frame, opposite the pulleys m and m, isa spiral spring 0, one end of which is secured to the sliding plate K ofthe holder, as shown in Fig. 3, and pivotally connected with the rearend of the main frame, or one of the legs thereof, is a pedal-lever P,provided centrally with a rod 19, pivotally connected at one endtherewith, and the other end of which is connected with the crank F inthe usual manner.

The grindstone may be revolved by means of the pedal-lever P, as will bereadily understood, or by means of the power lever or pulley G, to whicha belt may be applied, and said belt may be connected with a motor ofany desired form or construction.

The blade, bit, or other device to be ground or sharpened is insertedthrough the opening Z in the plate or bar L, as shown in Figs. 1, 3, and3, and held in position by the set-screw Z, and the operation will bereadily understood from the foregoing description when taken inconnection with the accompanying drawings. As the grindstone D isrevolved the cord 12, connected with the crank F and passing around thepulleys m and m, operates to draw the sliding plate K of the holder,together with the blade, bit, or other device to be ground, connectedtherewith in the manner described, to the right, while the spring 0operates to draw the same to the left, and thus at each revolution ofthe crank the sliding plate of the holder is oscillated, as will thereofwill depend upon the movement of the grindstonc or the rapidity of itsrevolutions.

The blade or bit R is supported within the slot or plate L, so that thesurface thereof to be ground comes in contact with the upper surface ofthe grindstone as shown in Figs. 1 and 2, and by reason of theoscillation of the frame or holder to which it is attached and themovement of the grindstone the grinding or sharpening of said blade orbit may be easily and quickly accomplished.

The position of the blade or bit within the holder may be regulated bymeans of plates S, as desired, and these plates may be formed of elasticmaterial, if preferred, and it will thus appear that I accomplish theobject of my invention by means of a device which is simple inconstruction and operation and one which is well adapted to accomplishthe object for which it is intended.

It is evident that changes in and modifications of the constructiondescribed may be made without departing from the spirit of my invention,and I therefore reserve the right to make such alterations in the form,construction, and combination of the various parts as fairly come withinthe scope thereof.

Having fully described my invention, I claim and desire to secure byLetters Patcut- The combination with a grindstone of the characterherein set forth, of the supporting frame, the actuating pedal leverpivoted thereto, supports having bifurcated lower portions, set-screwssecured Within said bifurcated lower portions to afford adjustments forthe same, transverse cross-piece provided with grooves, a reciprocatingplate having longitudinal projections adapted to engage said grooves andprovided with a central recess in which is secured a clamping-screw, anadditional crossrpiecc supported adjacent to said transversecross-piece, the spring 0011- necting said frame and the additionalcrosspiece, an extension of the transverse crosspiece,pulleys mounted insaid extension cords or ropes connecting the last-mentioned crosspieceover said pulleys to the crank-shaft of the grindstone, whereby whensaid crankshaft is operated the reciprocating plate is actuated,substantially as shown and described.

In testimony that I claim the foregoing as my invention 1 have signed myname, in presence of two subscribing witnesses, this 11th day of June,1895.

HARRY D. BLUMENFELD.

Vitncsses:

L. M. MULLER, M. A. KNowLEsJ

